(in this sanemi isn't twenty one he is fifteen so are you and nezuko)
Ever since you and Nezuko became demons it was hard yes. But you grew to the accustoms of being a human flesh eating monster as people described you. But in Tanjiro's eyes you couldn't even step on a flower or hurt a fly.
Once Tanjiro met Sanemi it was hard the first time they encountered "your carrying two demons! with you! come on! how can you call your self a pillar if your taking our enimes side!?" he growled. "Y/n and Nezuko won't hurt you even if you angered them they would protect you!" Tanjiro growled right back. Sanemi charged at the boy and forced his sword through the box that Nezuko was in. You were in the box and stopped the sword from going through her chest with your finger tip.
"H-huh!?" his sword was only just through the wood before he could force it in more when it was stopped. Nezuko clinged onto you shaking scared of the man who was out of his mind. "You demons! you should be killed sliced right off!" he threw himself back with a twitching eye.
"Sanemi! calm down!" Rengoku came and grabbed his arm but the white haired male slapped his away. "NO YOU WANT TO BE LIKE THAT I'LL KILL THEM MYSELF!" he once again ran at Tanjiro ripping the box off his back and stabbing holes in it. You were fed up with the utter bullshit this mad man was giving. So you placed your hood on that was on your kimono and opened the box.
He stepped back smirking with hungry eyes. A tail popped out then a small girl. You brushed off and stared at him straight forward creating a grim silence. You growled through the muzzle you were wearing and stepped forward.
Sanemi charged at you but you stopped the sword again with your finger. "How can you call your self a hashira when you don't even know me or my brother and twin" you tilted your head. He let out a low growl and dropped his sword in defeat. You shrunk again and crawled back with Nezuko hugged you and you hugged back in her warm embrace.
After the problem that you thought was over with you and Nezuko were tucked in together asleep while the others were eating. "Wow there Tanjiro your sister is quite the demon" Rengoku smiled. "Well she has always been so timid and shy she often is scared but ever since the demon thing she has changed alot" he shrugged with a smile.
After dinner everyone set them selves to sleep. But sanemi couldn't do it. He hopped out of bed and walked outside breathing in the cold air that stung his nostrils. He walked closer out to the forest he was so calm and out of his reality he was for once off guard. And he was caught off guard. A demon pulled him down to the dirt floor tackling him scratching and biting every place of Sanemi's body.
He struggled because the demons pure strenght he tried so hard but failed miserably. The demon bit a chunk of the boys back making Sanemi scream and howl loudly. You on the other hand were still awake and the scream was as clear as a blue cloudless sky.
You jumped out of your spot and booked it to the screams and growls. Once you made it Sanemi was in his own blood as the demon went to bite his neck. You ran to a tree jumpig high and pushing yourself off to get more speed and momentum in your attack since the demon was big.
You stuck your leg out while flying at the demon trying to devour Sanemi. Your leg had so much impact on the demon it was cut straight clean off. The demons head went bouncing then stopped and disappeared.
You picked Sanemi off who then kicked you off but was in to much pain to move. So you carried him back as fast as you could alerting the others. Rengoku took him to the beds where he tried his best to patch up the gaping wound on his back.
Everyone was on edge the rest of the night in the morning. You worried deeply for Sanemi even though he showed you coldness when you first met him. You still cared for him.
After three days of tension so thick you could cut it with a knife. Sanemi finally awoke but not in the most pleasant of ways he scared everyone in the place. "AAAAAAAAAAHHHHHHHHH!" he screamed he tried to move his back. You came bolting in to see him fall back down in defeat.
He scowled as you got closer to him. "T-thanks brat.." he murmurs inaudible. You nod with your eyes closed and then shrunk down to size. He was confused at your sudden actions and saw you crawl on to his lap. God you were small.
You huddled to his chest and he fell back onto the matress still showing a scowl that soon softened.
